Control means for variable-pitch propellers



May 18, 1948. H. OBRIST v CONTROL MEANS FOR VARIABLE-PITCHPROPELLERS I Filed Feb;

6, 1946 2. Sheets-Sheet 1 lnuznior h Obr Aitiornegs Heinrtc May 18; 1948. H. osRls'r CONTROL MEANS FOR VARIABLE--PITCH PROPELLERS 2 Sheets-Sheet 2 Filed Feb. 6, 1946 Inu cifior Heinrich Obrisi:

Alicrncgs I Patented May 18,1948 2,441,838

CONTROL MEANS FOR VARIABLE-PITCH PROPELLERS Heinrich Obrist, Zurich, Switzerland, assignor to Escher Wyss Maschinenfabrlken Aktiengesellschaft, Zurich, Switzerland, a corporation of Switzerland Application February 6, 1946, Serial No. 645,771 In Switzerland February 3, 1945 Section 1, Public Law 690, August 8, 1946 Patent expires February 3, 1965 Claims. (01.170-163) v1 7 v This invention relates to control means for Springs and shown in difierent working positions variable-pitch propellers, especially for marine in the two figures.

propellers, which means comprise a reversible Fig. 6 shows a second embodiment of the inelectric motor serving to vary the pitch of the vention, and blades and an operating lever which determines 5 Fig. 7 shows a detail of this second embodithe rotation of the said motor and the angular .mentinsection.

adjustment of which indicates the magnitude In Fig, 1 of the drawing I denotes a variableof thevariation in pitch of the blades aimed at pitch propeller, which is connected by a hollow in each particular ease, V shaft 2 to a shaft section 3, the latter being in The object of the invention is to provide con- 10 -tum driven by a shaft 4. Into the shaft section trol means of this kind which shall be simple in 3 above mentioned is built in well known way.

construction and will work in a safe and effecan electric motor 3i driving a pump3 which tive manner. For this purpose according to the supplies liquid under pressure for shifting the popresent invention the operating lever is mounted sitionof "a servomotor casing 3 also arranged between at least two contacts "of a rotatably 16 in the interior of the shaft section 3. To this mounted, forked-shaped contact carrier. This casing 3 is rigidly connected a rod 5, so that the contact carrier is moved, after the electric motor. movements of said casing v 3 are imparted to has been switched into circuit, through a transthis rod. The latter is in operating connection mitting mechanism by a member operated in dewith the blades of the prop ller o th t when pendence on the variation in the pitch of the $0 the rod 5 moves lon t d nally these blades have blades which is taking place, such movement of a corresponding pitch changing movement imsaid contact carrier being in the direction in parted to them. This mechanism for hydrauliwhi h th -c nta t o e a cally varying the pit'ch'of the propeller l is of While being moved in the direction in'which the construction described and claimed in my the contacts close, the operating lever may conapplication Serial No. 604,47 filed July 11, 1945, veniently effect, throughan equalising device, a and since its details do not form Part Of the shortenin of the mechanical connection between present invention they ed not be set forth in the contact carrier and the member operated r t de ail. The movement of a ring 6 is also in dependence on the variation in the pitch of derived from the operating .rod 5, to which it is the blades, in which case this shortening is then connected by a follower 1. 8 denotes'slip rings, gradually. nullified automatically until the varlathrough which the motor 3 in the shaft section tlon in the pitch of the blades corresponding 3 receives current. In operative connection with to the movement of the operating lever is the ring 6 is alever 9, which, in coopertaion with reached, with the result that the contact conn a transmitting device constituted bya rod l0 and nection between the operated operating lever and a bell crank lever I l transmits longitudinal movethe contact carrier is then released, ments of the ring 6 to. a rod l2. This latter is constructional forms of the subject matter of rigidly connected to the spring housing I! of an the invention are shown in the drawing in which: equalising device. In the housing or box I1 is Fig. 1 shows, in simplified form, partly in longi-' mounted a piston I2 which is adapted to move tudinal section and party in elevation avariable- 40 longitudinally and is acted on by two initially pit-eh ships propeller and an electric controlling equally stressed springs I2 and I2 Said pismechanism which controls the working of a ton ll-"l l o connected rigidly y a r I2 to mechanism for varying the pitch of the propeller arctatably mounted contact carrier I3 constructblades. 7 ed in the form of a forked lever. On the contact Figs. 2 and 3 show the operating lever in the carrier I3 are mounted two groups of contacts positions in which. respectively the propeller 21 an 2 tw en which. a lever l4, provided blades are adjusted for the ahead and astern with a handle l5 and a locking detent I6 is likemovement of the ship. wise mounted to rotate. On this lever M are Figs. 4 and 5 aresections through'an equalising mounted two groups of switch contacts I4 and device provided with a piston controlled by two lflrespectively. The arrangement is such that 2H, 21 of the fork carrier I3 are connected through conductors 23 and switches .24 to the brush holders 25" ofithe'rnotorysh- :Between -tlm contacts of the groups I4 and 2l an'd le i and. 21 respectively, are arranged springs I '(Figs.

2 and 3) which are weaker than the springs 12. .5 5 E2 and which tend to maintain normallyacleare,

ance s (see Fig. 1 of about'l' mm; between the: x

groups of contacts in question. This clearance" s can be varied by means. of-:. a; screwdt'k If therefore the lever M for example begmovedizoufi of its central position shown' in -Fig'. 1; which?" position corresponds to the stop position S, the

clearance 8 must first be bridgedbefore-the. con-p tacts of groups M and zl 'andl l and 'fZ'JIQirespectively will come into engagement. Only then will the motor 3 in the shaft 'sectio'nz 3 1 and, only then will the adjustment ofthe blades of the propeller I into the desired position be initiated.

Accordingtothe desired directionof adjustment of theblades'of' propeller I the'h'andle' lfi must be brought out of the stopposition S'either into the position V (Fig.2) for runnin ahead of position R (Fig.3). for running ast'ernzj Assuming thatthe switch' lever 14' hasjbeen moved into the position V shown in Fig. 2, and-that this movement'ofithe' lever has caused the motor}? to start runningas soon as j the clearance s has been overcome; the ring. 6"canj,"for the present; not follow the movement. of theswitcli lever l4. quickly enough so that" theiendf 2610f" the lever acts as a. fixed point" as regardstheparts' l2; l'l, 52 The result of this'isi that onthe rapid movement of the switch levertl'll, [5 out of? the; position. s into the; position" V." the piston'1l2 of the equalising device'vvill .be"imoved' down wards 'relatiye to the box; I"! whereby the spring 4 2 *willb'ei compressed" and; the" spring, I 2 on the other handiallowedtmexpand ('seeFigtU'. This results" in? a shorteningot the 'mechanical con nectionibetween the contact:v carrier" I 3" and," the rings: During the furtliervariation'ef 'thepitch of thebladesof' the propeller the ring't' 'ismoved' in: the direction ofthei'axis' oii'the shaftizinsuch 4 produced when the handle. I5 is moved into the position V. In other respects the operations take place as required in the corresponding way, as above described,

The arrangement may also be built in such a way that the operating lever worked by a handle controls only the flow of controlling currents, WhilGiFt'h'B0111336111}WhiCh il'GlflSESWHQHIOiOI movemerits canibe controlledsby a relay; This latter is in such a case influenced by a controlling current Which is under the control of the above mentioned operating lever.

Such" anembodiment is shown in Figs. 6 and 7;"wherein the parts which correspond to those in- Figs:.-I'to" 5:are:den'oted by the'same reference rrumbersgni'I'lreablade adjusting mechanism proper correspon'dsZ td' -that: illustrated in Fig. 1. Thus in Fig. 6 tlie'nume'ra-l 3 denotes again the electric motor builtdnrthenshaft section 3 and 4 designatesl the driving shaft, 5 the operating rod and Q the ring whose movement is derived from the roid tl by: -m*eans= of a follower l. The numeral ii -designates the lever which is in operative connection with the ring 6 and: the movements of which are transmitted by a rod. Ill to a bell crank lever II. The latter acts in.this embodiment .directly"on"thej casing i I"! orthe equalisinlg .device, the. piston?! 2 ofwhich'is' com ected' rigidly by the. 1'Q'd".lZ* tQ thf UOI1taCt carrier 93 rotatably mounted jon' the: shaft f'3llf and} having] thef orm of. a forked le whicli has a 'right hand'ed? and 'a: lefthanded" threjacland allowsiofi varying the length"; of" the rod 12*: The bell crank lever; l I isfia'lso operatively connected to aJever3-]fwhichiniiitsfturn is conne'ctedrby' a will: to a lever-33 pivote Jon.

the: above mentioned-shaft. 30?: The. outer? end a Way thatthe'lever 9"isi rdclzedf in: a clockwise 7 direction. soon as this lever' 9" assumes the position which corresponds tb theV" position'ofthe. switch lever. I l5, the" spring. I 2 will have expanded to such"; an extent 'thatith'e parts 12 52%123" andJlTwilI have assuniedwithrespect to: veac'lr'other the position shown. iii'Fig; The: shortening above mentioned of "themechanicalf V connectionfbetween the contact carrier I3 "and? thering 6 1s consequently again automatically. nul'lifiecl and the springs l '5 jarranged between tlie'icbntact groi'ip'sM1. and 21?" are. now abl e t'o remove thev righthand forked part ofthe contact" carrierJSi away from the switch lever .I fbyjjth'ei amount of the slight clearance s referredto s ave; so'that' the supply." ofijcurre'nti .to' the material will'be interruptd and the. adjustment. offth'e,

propeller blades .in tl ie direction irf questionin terr'upted'al'so. I r

If the. handle. 15' an therewith sses switch.

lever-T i l. be brought into the position R: shown in" Fig.3; the motor 3 will be 'drive'ri in the'oppo. site direction t'o'th'at in which" itiha'si run hith 1 erto, so.- that the blades of'the TprOpeIle rQ'IYQWiHl co=operating withtwo terminal switches: 35 and. 35 respectivelyr the contacti'fcarrier [3i are:

mounted: two contacts. designed as. adjusting screws '3 6?? and 316 5," e'acltof which" 5 co {operates with an ailottedz'snapiswitch' 31 3" andj3l respectiv'elyi off'gconventibna l" design, These snap switche's contrjol the flow: of" an; electric current ther fitted with two magnetic s lenoids 4m and which serve? as means afar actuating. the.

switchestea ji'fill? andithe; excitation. of which. is;

controlled 1 'by ftl'ief snap switches any-1351 re.

spectivelyl The" numeralifl' designates; ahand operated switch mountedlih the. inainiNTj" "It? the" svvitchfleVel l .4 by. means of we handle- Isis: moveme t in: the" stop. position. ST-"sho'wn in; Figififih "the; direction v; for. running. ahead the. snap switch wllliheclosed; tha'smalliclearance s between switclil-lever. 1' 4 and contact; carrien I31 beingv simultaneously overcome; The result of heath that. dscribedlin'. connection with-,E'iga 1, the. opening of the snap.switch-.--3l. are-soon; as

the blades have been displaced into the desired p sition. lmmediately before til-i51 is the; case, the. contact screw will disconnect from. the

l2 designates a:threaded sleeve;

snap switch 31 the contact carrier l3 having in the meantime been displaced. automatically in such a sense that; said small clearance 5 above mentioned is re -established before the screw-36 disconnects from the snap switch3'l V If the switch lever 14 is moved in the direction R bymeans of the handle 15, the snap switch it! and the switch 39? will be closed, sothat the motor 3 then rotates in a sense opposite, to that,

magnitude of the blade adjustment aimed at;

two groups of switch contacts mounted onoppositesides' of saidc e'rannguever: a rotatable; forked-shaped contact carrier having at least two contacts between which said contacts mounted on the operating lever are adjustable; means tending normally to maintain clearances between the contacts of said operating lever and of said carrier, said motor beingswitched'in as soon as one of these clearanceshas been bridgedowing to said operating lever having been moved out of its central position; a mechanical transmission mechanism operatively connected both to said movable element effecting pitch changes and to said contact carrier, the latter being moved, after said electric motor has been switched on, in dependence on the blade adjustment, in the direction in which the contacts in question are again opened; and means incorporated in said transmission mechanism and adapted to overcome the tendency of said means to maintain clearances between the contacts of said operating lever and of said carrier.

2. In a variable-pitch propeller and control mechanism therefor in combination, a plurality of propeller blades rotatably supported for pitch changing movement; a mechanism having a movable element operatively connected with said blades for effecting pitch changes; a reversible electric motor for actuating said mechanism; an operating lever which determines the rotation of the said motor, the angular adjustment of said operating lever indicating in each case the magnitude of the blade adjustment aimed at; two groups of switch contacts mounted on opposite sides of said operating lever; a rotatably, forkedshaped contact carrier having at least two contacts between which said contacts mounted on the operating lever are adjustable; means tending normally to maintain clearances between the contacts of said operating lever and of said carrier, said motor being switched in as soon as one of these clearances has been bridged owing to said operating lever having been moved out of its central position; a transmission mechanism operatively connected both to said movable element efiecting pitch changes and to said contact carrier, the latter being moved, after said electric motor has been switched on, in dependence on the blade adjustment, in the direction in which the contacts in question are again opened; and an equalising device incorporated in said transmission mechanism producing, when said operating lever is moved in a direction in which said contacts are closed, a shortening of themechanical connection betweensaid contact carrier and said movable element eiiecting pitch changes, said shortening being gradually nullified automatically until the blade adjustment corresponding to the movement of said operating lever is attained, whereupon the connection between the moved operating lever and the contact carrier is released.

3. Ina variable-pitch propeller and control mechanism thereforin combination, a plurality of propeller blades rotatably supported for, pitch changing movement; a mechanism having a movable element operatively connected with said blades for efiecting pitch changes; a reversible electric motor for actuating said mechanism; an operating lever which determines the, rotation of the said motor, the angular adjustment of said operating lever indicating in each 'case the magnitude of the :blade adjustment aimed at;

two groups of switch contacts mounted on opposite sides of said operating lever; a rotatably, forked-shaped contact carrier having at least two contacts between which said contacts mounted on the operating lever are adjustable; springs inserted betweensaid contact carrierv and said operating-lever and tending normally to maintain clearances between the contacts of the carrier and of the operating lever, said motor being switched in as soon as one of :said clearances hasbeen bridged owing to saidv operating lever having been moved out of its central position; a mechanical transmission mechanism operatively connected both to said element eiiecting pitch changes and to said contact carrier, the latter being moved, after said electric motor has been switched on, in dependence on the blade adjustment, in the direction in which the contacts in question are again opened; and an equalising device incorporated in said transmission mechanism producing, when said operating lever is moved in a direction in which said contacts are closed, a shortening of the mechanical connection between said contact carrier and said movable element effecting pitch changes, said shortening being gradually nullified automatically until the .blade adjustment corresponding to the movement of said operating lever is attainedv whereupon the release of the connection between said contact carrier and said operating lever is effected by said springs.

4. In a variable-pitch propeller and control mechanism therefor in combination, a plurality of propeller blades rotatably supported for pitch changing movement; a mechanism having a movable element operatively connected with said blades for effecting pitch changes; a reversible electric motor for actuating said mechanism; an operating lever which determines the rotation of the said motor, the angular adjustment of said operating lever indicating in each case the magnitude of the blade adjustment aimed at; two groups of switch contacts mounted on opposite sides of said operating lever; a rotatable, forkedshaped contact carrier having at least two contacts between which said contacts mounted on the operating lever are adjustable; means tending normally to maintain clearances between the contacts of said operating lever and of said carrier, said motor being switched in as soon as one of these clearances has been bridged owing to said operating lever having been moved out I and: to said a contact carrier;- the latter: being move'dgy after= saidi e1ectrie moton g-hasfibeen switchedi on, in dependence onthe i blade 1 ad'iust mentg; in1theidirection in Wl'liClT- the contactsin" question: are again opened; a piston-"connected rigidly to: said contact carrier; a: sleeve -in' which said; piston is mounted; two initially equally stressed springs housed- Within said sleeve-and acting on both sides of said piston; and a; sys tem of rods and: levers connecting: said sleeve to saidmovable element efiecting pitch changes;

5;:In1 a lvariable pitchpropeller and control me'ohanism therefor: in" combination, aplurality? off. propeller blades rotatabl'y supported -for piton changing movement; a mechanism; having a w movable element i operatively connectedwith said blades for effectingpitch changes; areversible elect'riomot'or for actuating saidmechanism;-arroperating lever which controls the fiow'ofcon trolling currents and the" angular displacement' oftwhichiin'dicates in each case'the magnitude of" the; blade adjustment aimedat; a relay con trolling-the current which releases said electrio" motor; and. influenced in' its-turn by said controlling. currents; switch: contacts mounted on said a operating lever; a rotatable; forked shaped con tact carrier having'contacts between-which are mountedl said switch contacts provided on the operating lever, clearances being normally pres enti between the contacts of the latter and the-- a v 80 contacts mounted on said carrier and one=-of' said controlling currents being switched in'-as-' seem as one}of thesei'clearances-has been bridged o said operating lever having been movedowingunit of its: central position; a mechanical trans- .mission mechan-ism operatively connected both to said movabl'e element: effectingpitch changesand to said contact-carrier, the latter: being movediaft'ersaid eleetric motor' has beenswitched ongl' iir'dependen'cw onzthe 'b'l'ade" adjustment; in

the direction-m which the contacts in question lfl 'are again opened; and means-incorporated in" said transmission mechanism'and adapted to overoom'e th'e' tendency of" saidgmeans to main- 7 tain clearances between the contacts off said operating lever andfofsaid carrierfi HEINRICH OBRIST;

CITED? Theafollowln'gi references" are of record in the 0mm REEERENCES:

semen" May 18, 1943{= aiaiwyse lerma P: 0.) published" 

